In general, talking on a cell phone while driving a vehicle requires several simple stages including pressing buttons or touching the cell phone in a hand-held state, and talking on the cell phone with a counterpart while holding the cell phone to an ear of the driver.
Unless the vehicle stops or parks at a place, at least one of the hands of the driver needs to hold the cell phone while talking on the cell phone.
In this case, since the driver may have a narrow field of view and cannot pay full attention to objects nearby, the vehicle may deviate from a travel lane, and reaction time on the brake pedal may increase, causing increase of traffic accidents.
A hands-free device is a device used together with a cell phone that allows the driver to talk on the phone without holding the cell phone to reduce the provability of car accidents.
That is, the driver may talk on the phone without holding the cell phone by mounting a hands-free device including a microphone and an ear phone (or speaker) to a vehicle and connecting the hands-free device with the cell phone via a cable.
However, due to inconvenience of directly connecting the hands-free device with the cell phone by using the cable, Bluetooth devices using Near Field Communications (NFC) have been developed in recent years.
A Bluetooth device includes a microphone and an ear phone (or speaker) and communicates with the cell phone wirelessly.
The hands-free device and Bluetooth device perform transmission and reception of voices of a user and a counterpart while performing speech recognition by collecting a voice of the user and communicating with the cell phone based on an operation command corresponding to a recognized speech.
In this regard, the hands-free device and Bluetooth device transmit voice signals of the user to the cell phone and output voice signals of the counterpart received from the cell phone via a speaker.
In addition, speech recognition may also be used to control operation of electronic apparatuses installed in the vehicle such as a multimedia playback apparatus and an air conditioner.
For example, the multimedia playback apparatus recognizes a speech of the user, determines an operation command corresponding to the recognized speech, and performs at least one function based on the determined operation command.
When speech recognition is used to control operation of at least one electronic apparatus as described above, a speech recognition rate may be reduced due to noise from roads or noise signals from internal machines inside the vehicle.